Chronic obstructive pulmonary disease (COPD) is a term used to classify two major airflow obstruction disorders: chronic bronchitis and emphysema. Approximately 16 million Americans have COPD, 80-90% of them were smokers throughout much of their lives. COPD is a leading cause of death in the U.S., accounting for 122,283 deaths in 2003. The cost to the USA for COPD was approximately $20.9 billion in direct health care expenditures in 2003. Chronic bronchitis is inflammation of the bronchial airways. The bronchial airways connect the trachea with the lungs. When inflamed, the bronchial tubes secrete mucus, causing a chronic cough. Emphysema is an overinflation of the alveoli, or air sacs in the lungs. This condition causes shortness of breath.
In emphysema, the alveolar sacs are overinflated as a result of damage to the elastin skeleton of the lung. Inflammatory cells in emphysematous lung release elastase enzymes, which degrade or damage elastin fibers within the lung matrix. Emphysema has a number of causes, including smoking, exposure to environmental pollutants, alpha-one antitrypsin deficiency, and aging.
There are no therapies available today to halt the progression of COPD. Inhaled steroids have recently been studied (Lung Health Study II) as a potential therapy to prevent loss of lung function in emphysema patients. The study concluded, however, that inhaled steroids failed to alter the decline in lung function over time. As patients lose lung function over time, they may become dependent on oxygen, and eventually end up on ventilators to assist with respiration. A relatively new treatment for patients with emphysema is lung volume reduction surgery. Emphysema patients suffer from air trapping in the lungs. This flattens the diaphragm, impairing the ability to inhale and exhale. Patients with emphysema localized to the upper lung lobes are candidates for lung volume reduction surgery, where the upper lobes are surgically removed to restore the natural concavity and function of the diaphragm.
Acute exacerbation of asthma is often caused by spasm of the airways, or bronchoconstriction, causing symptoms including sudden shortness of breath, wheezing, and cough. Bronchospasm is treated with inhaled bronchodilators (anticholinergics such as ipratropium and beta-agonists such as albuterol). Patients inhale these medications into their lungs as a mist, produced by either a nebulizer or a hand-held meter dose (MDI) or dry powder (DPI) inhaler. Patients with acute episodes may also be treated with oral or intravenous steroids that serve to reduce the inflammatory response that exacerbates the condition.
Asthma is a chronic respiratory disease characterized by inflammation of the airways, excess mucus production and airway hyper responsiveness, and a condition in which airways narrow excessively or too easily respond to a stimulus. Asthma episodes or attacks cause narrowing of the airways, which make breathing difficult. Asthma attacks can have a significant impact on a patient's life, limiting participation in many activities. In severe cases, asthma attacks can be life threatening. Presently, there is no known cure for asthma.
According to the American Lung Association, there are approximately 20 million Americans with asthma in 2002. Fourteen million of them were adults. Asthma resulted in approximately 1.9 million emergency room visits in 2002. The estimated direct cost of asthma in the U.S. is $11.5 billion, which is spent on asthma medications, physician office visits, emergency room visits and hospitalizations.
The causes of coronary heart disease and asthma are neointimal proliferation of smooth muscle in arterial vessels and in walls of airways. One aspect of the invention is to deliver paclitaxel or rapamycin and their analogues to the wall of airways to treat the asthma and COPD. Drug coated stents with these drugs have been approved for inhibiting the growth of the smooth muscle cells in vascular arterial vessels.
Chronic sinusitis is an inflammation of the membrane lining of one or more paranasal sinuses. Chronic sinusitis lasts longer than three weeks and often continues for months. In cases of chronic sinusitis, there is usually tissue damage. According to the Center for Disease Control (CDC), thirty seven million cases of chronic sinusitis are reported annually.
Chronic sinusitis is often difficult to treat successfully, however, as some symptoms persist even after prolonged courses of antibiotics. Steroid nasal sprays and prescribed steroids are commonly used to treat inflammation in chronic sinusitis. When medical treatment fails, surgery may be the only alternative in treating chronic sinusitis. Presently, the most common surgery done is functional endoscopic sinus surgery, in which the diseased and thickened tissues from the sinuses are removed to allow drainage. However, there is a need for better medicine for chronic sinusitis.
The present invention provides a new method for treatment of respiratory disorders such as asthma, chronic obstructive pulmonary disease, and chronic sinusitis. The method involves administration, preferably oral, nasal or pulmonary administration, of anti-inflammatory and anti-proliferate drugs (rapamycin or paclitaxel and their analogues) and an additive. Embodiments of the present invention provide a pharmaceutical formulation comprising a drug for treatment of the respiratory system, and an additive that enhances absorption of the drug into tissue of body passages.